#define _CRT_SECURE_NO_WARNINGS 1

#include<iostream>
using namespace std;
int main()
{
    double money;
    cin >> money;
    double cost = (140 + 70 * 0.5 + 30 * 1) * 1.2;
    int maxnum = static_cast<int>(money / cost);
    cout << maxnum;
    return 0;
}